Apparatus for testing gear wheels



Feb. 6, 1923. 1,444,470)

.J. LAESSKER APPARATUS FOR TESTING GEAR WHEELS Filed Aug. 2, 1921 2 sheets-sheet 1 INVENTOR Jeauz Laefisker' BY MWM M ATTORNEY Feb. 6; 1923. 11,444,470

\ J. LAESSKER APPARATUS FOR TESTING GEAR WHEELS Filed Aug. 2, 1921 2 sheets sheet 2 lNVENTOR Jean/ Ldessfsefi ATTORNEY Patented l eb. ti, lglz b SEAN LAESSKEB, 6F ARBON, SWITZERLAND, ASSIGNGB T SDCIETE ANONYME ADOLPHE GE ARBOR, Sil A COEIPOEIATION 01* THE S'WISS CONFEDEEAGY.

snnnnn,

AFPA'RATUS FOR TESTING- Application filed August 2, 1921. Serial No. 489,171.

1 0 all wire 1'11 it may concern:

Be it known that l, Lsnssnnn, a subject to the Kin of tiweden, and resident of Arbon, Switzerland, have invented cer- 5 tain new and useful Improvements in lipparatus for Testing Gear Wheels, of which the following is a specification.

'lhis invention is an improvement in apparatus for testing toothed gear Wheels toascertain possible inaccurac in the shape or fault in the design of the teeth thereof, and relates more particularly to that type .iratus 1 which a pair of gears to be testeth'one of which may be a master gear,-

rotated tions in i: A de ce oi this general t ype is described and c med in the ilippolyt Saurer Patent No. 1,2 23,4?2, sued April 18th, 1918, and reissueo Decen' :1 21st, 1920, as No. 15,013.

in sp ci c form there illustrated, a ictiou disl-zs are employed which correspond in diameters to the pitch di- 25 amcnrs ol' the two gears and the substitution of gear oi diiierent pitch diameter requires a corresponding substitution of its respective dish.

The main objects of my invention are to avoid. the necessi y of this substitution or torchange of parts each time a gear of rent diameter is to be tested, and to permit of the testing of gears of dii'i'erent dian ters by an adjustment rutherthan a substitution of parts. j i As in said patent, l preferably employ a pair of rotating members mounted coanially, one being driven from the axis of one gear and the other from the axis of the other 40 gear, and indicated or recorded variations in the relative rates of rotation of these members result from; and correspond to, :z-articular term or shape of the teeth of while in proper mesh, and variat e rate of rotation of one in reoct to the other indicated or recorded.

justment or. the motion transmitting mechanism to an extent corresponding to the difference in pitch diameters of the gears.

in i s preferred embodiment, the motion transmitting mechanism from one gear includes a lever member, the power or leverage ratio of Which may be adjusted in accordance with the diameters of the gear Wheel. A change in the ratio of the diameters of the two may thus be compensated for by adjustment of the transmission ratio of the lever member.

A further object of my invention is the provision of adjustable lever mechanism ch will operate at .-various different power transmitting ratios and Without lost motion or binding or jamming of the parts. I may advantageously accomplish this result by novel form of double lever having longitudinally adjustable arms separately connected by coupling rods With friction r disks, one rotated by one gear shrill and toe other serving to rotate the coo-resbonding rotary member of the indicating or recording devices. By the simple expedient oi longitudinally adjusting the point ot engagement of said rods With said ioror arms radially in respect to the fulcrum of movement of the lever arms, the iission ratio from one rod to the other may quickly and easily adjusted at Will. The adjustment of the point of engagement '"JOti; to the fulcrum may be easily aclished by a bodily adjustment of one or 1 lever arms 'endwise in respect to a can rier at, or constituting, the fulcrum. By the use of proper indicating scales, the proper adjustment of the lever arms may be quickly made in accordance with the known gear ratio of the pair of meshing gears being employed or tested. The device is rendered particularly compact and the source of error in the transmission of motion to the indicating apparatus eliminated by mounting the two urn. the double lever one above the other in a rotatable guide having means for rapidly securing them in adjusted position including a shaft 18 and a sleeve 19.

tested. This is secured by mounting the indicating mechanism at the desired dis tance from the gear carrying spindles, and connecting the rotating parts of the indicating mechanism to the rotating gear supports, by means of longitudinally moving coupling members.

Inthe accompanying lustrated a device constructed in accordance with my invention, alternative forms of some of the parts being illustrated. In these drawings,

Fig. 1, is a perspective view of a device, portions thereof being broken away.

Fig. 2 is a plan view of a slightly modified form,

Figs. 3, 4t, and 5 are sections on the line 33, 4-4, and 5-5 respectively, of Fig. 2, and

Fig. 6 is a perspective view of a slightly modified torm of one detail.

The operating parts of my improved device are mounted on a suitable frame which is. preferably in the form of a casing 10 which will conceal and protect the parts. This casing or frame carries a pair of spindles 11 and 12, upon which the two gears 13 and 14% to be tested are mounted. One of these gears, for instance the gear 1 1, may be a master gear with which various di' erent gears may be mounted in meshing relationship for test purposes. The two spindlesare adjustable toward and from each other to accommodate gears of different diameters; Any suitable means may be employed for accomplishing this, as for in stance the spindle 12 may be mounted on a slide orcarriage 15, movable in guides 16' on the body of the casing. The adjustment of the slide or carriage may be accomplished by means of a screw rod 17 mounted in one end: of the casing and having threaded engagement with. a lug rigid or integral with the slide 15.v This screw rod may be operated in. any suitable manner, as for instance by a crank or handwheel. j

The two spindles are mounted adjacent to one end of the casing and the indicating mechanism may 'be mounted adjacent to the opposite end. This indicating mechanism includes a pair of coaxial rotatable members One of these is driven from the spindle 11 and theother from the spindle 12, and the driving or motion transmitting mechanism is such that any irregularity, inaccuracy or defect in the shape or contour of the teeth of either or both gears will cause a variation in therelative rates of rotation of the members 18 and 19. I do not wish to be limited to any specific form of indicating means.

.The specific means employed will vary depending. upon whet-her it is desired to merely give an indication, or whether it 1s des1red to malnea record of the result of the test.

drawings there is il- 'The two coaxial relatively rotatable members may be coupled to such an indicating and recording mechanism as that shown in the Saurer patent above referred to, or may be coupled to a simpler form of mechanism which indicates but does not record;

Merelyfor purposes of illustration I have shown the sleeve 19 provided with a dial 20 having suitable graduations or indications thereon, and the shaft 18 is provided with a pointer 21. The rotation of the two members 18 and 19 at the same uniform rate will hold the pointer in a constant position on the scale of the dial 20, but any variation in the rate I of rotation will cause a relative movement of the pointer and scale.

One of the important teatures of my invention involves the means for transmitting motion from. the gear spindles to the coaxial indicator members and to permit of an adjustment of the transmission ratio at will.

The motion transmitting mechanism as illustrated, includes a pair of friction disks 22 and 23 mounted on the shafts 2 1- and 25 which carry the spindles 11 and 12,'and a second pair of friction disks 26 and 27 mounted on the shaft 18 and sleeve 19 of the indicating mechanism. Separate means are provided for transmitting. motion from the disk 22 to the disk 26 and from the disk 23 to the disk 27. The means for adjusting the transmission ratio may beemployed in either or both of these motion transmitting connections and may he usedsingly or in series in either or both. I have i-lli-istrated the motion ratio adjusting mechanism employed in only one of the motion transmitting connections. Where no adjustment is employed, a rod 28 may be mounted so as to act in frictional engagement with the peripheries of the two disksas for instance the disks 23 and 27. This rod may be held in frictional engagement with the two disks by pressure idler rollers 29 held against the rod 28 by suitable springs. It is of course essential that the peripheries of the disks be ground true, and that the faces or. the rods be also accurately formed. It will of course be evident that any other suitable means might be employed for transmitting the motion from the disk 23 to the disk 27.

Where it is merely desired to separate the indicating means-from. the vicinity of the being tested the same means abme described may be employed for transmitting motion from the disk 22. to the disk 26. and

guide block 37 carried by a pivot block 38 mounted in the frame or casing of the apparatus, and at some distance to oneside of the general position of the rods above referred to. The lever 35 has a roller 39 engaging with the transverse face of the rod 30, and the lever arm 36 has aroller 40 engaging with the transverse face of the rod 32. The two lever arms are spaced a short distance apart, vertically, and therefore the two rods 30 and 32 are likewise spaced for proper engagement with the rollers. With the two rollers at the same distance from the fulcrum, namely the axis of the pivot block 38, any movement of one of the rods 30-32 will result in a corresponding move ment of the other. By adjusting one roller nearer to or farther from the lever fulcrum, there will be a corresponding variation in the relative endwise movement of the two rod sections. 1 do not wish to be limited to any particular means for varying the relaative position of the rollers in respect to the lever fulcrum, nor do I wish to be restricted tothe use of rollers against other forms of hearing or contact means reasonably free from friction losses. It is more convenient to secure the adjustment by the bodily endwise movement of one or both of the lever by means of which the distance between the axes of the spindles 11 and 12 or the ratio of the diameter of a gear to be tested to the diameter of a master gear, may be readily ascertained when the gears are in proper mesh. The upper lever arm 36 and the guide block 37 may have similar scales s3 and A, indicating the longitudinal adjustment of the lever 36, and these scales may be calibrated to read in gear diameter ratio so that when the two gears are brought into proper mesh. the lever arm' 36 may be adjusted endwise until there is the same reading on the scale 43 as there is on the scale d1. -i fith this calibration and adjustment, the rotation of the two gears will give substantially the same rate of rotation to the pointer 21 and dial 3", hut inaccuracies in the teeth formation will cause the relative back and forth movement of the pointer over the scale.

With my improved construction, it is not necessary to remove or substitute any parts of the apparatus when it is desired to testgears ofdill erent diameters. lt is merely necessary to make the proper adjustment of the motion'transmittf mechanism. It will of coursebe evident that for comparatively small variation in gear sizes the longitudinal adjustment of one lever arm is sufiicient, but for wider variation both lever arms may be adjusted one in one direction and the other in the other dircction. l urtheri'nore, there may be provided a series of master of different sizes, and thus the apparatusneed be adjusted only to take care of variations in gear ratio between those variations accomplished by substituting different master gears. Even with the substitution of master gears, it is not necessary to change the f iction di ks or other operating parts within the casing.

I do not wish to be limited to the specific construction illustrated, as various changes may be made. The two rod sections 30 and 32 may be held against the rollers 39 and to in various dif erent ways, as for instance by means of a spring as shown in Fig. 1, or by forming channels 46 engaging with opposite sides of the rollers, as indicated in 6. Although it preferable to have'thc plane of the axes of the spindles parallel to the direction of movement of the slide or carriage 15, as indicated in Fig. l. so that the scales may show the exact charge in position of one spindle in substituting a gear of different diameter the plane of the axes may be at an angle to the direction of moveir of the slide or carriage 15, as indicated Fig. 2. It is merely necessary that the opposits directional rotation of the disks and 23 transmit imidirectional rotation of the disks 2-6 and 27.

It is thought that the o,- i'lls device .vill be sufficiently clear 1- the foregoing description, but may be bri-ell paits 23, 2d. Eland to the dial :2 With the upper lever arm 30 adjusted end position the mtation of isniitted through the and wise to the pro the gear it? will be darts 2%, 2L, Y0, lll, 32. 2d d to the pointer. f the adji i ever arm has been proper ars are ahcurately formed ill rotate ;he age ewti've. or l e i are luau-curate, there --1.:, i an oscillation 4;! ail" i j upon the scale during;

been properly made, the pointer will rotate faster or slower than the dial. This may be readily corrected by readjusti'uent of the lever arm. lithe fl 1011 dishs 22 and 23 be of theisame diam .ter and the disks 26 and 27 be of the same diameter, and the lJWO gears be of the same (liaiiioteir,ll1e11 the two I rollers- 39 and l can be aijljustcd tothe same tatablc distance from the ti'ilcrum or aiiis of the pivot block 38. lVith the parts of these relative proportions, a change of the I or 13 to a longer or nnallor size will require an adjustment of one lever arm in respect to 1 the other, to such an extent that the ratio of the e ective lengths-i or the lever arms Will correspond with the ratioo'f the gear diametors. it will of course be evident that the various friction disks may be made of; dit 'l'eiiciit diameters, and this may be desirable in order to maintain the transmission ratio Without Wide variation in the lengths of the lever arms, Where it is desired to test gears a great deal larger or a great deal smaller than the master gear. Although the lever arms are illustrated substantially in superposed and approximately parallel. relationship, it Will of course be e\ 'idont that this not essential, as they may be arranged at a considerable angle to each other.

The simple mechanism illustrated is free oi any lost motion, and the parts are so designedand mounted that there is no liability of binding; or jamming du ino; adjustment of the parts.

llaving thus described my invention, What I claim as new and desire to secure by Letters Patent is:

l. A gear testingapparatus including rotatable supports for a pair ofmeshing gears, lndicating mechanism IHClUFllHQ, coaxial members, and means for transmitting motion from said supports to said members, and including an adjustable part ivl'iereby the motion transmitting ratio may be varied.

it. near testing apparatus including rotatablc supports for a pair of meshing gears indicating mechanism including coaxial rotatal'ile parts, means for transu'iitting motion from one support to its corresponding part, and means for transmitting motion from the other support to the other part, one or said means ci ig adapted for the admat of the motion transmitting: ratio. 3. A gear testing apparatus including rotatablc supports for a pair 01": meshing gears, indicating mechanism. means for transinittiiuz motion from one of said supports to said inoicatingr mechanism, and adustable means for transmitting motion from the other sugport to said indicating mechanism and at var-yumrates, dependent upon the relative pitch diameters of the gears.

ting apparatus including rosupports for a pair of meshing gears,

ees r indicating mechanism and means for transmitting; motionfroin said supports-to said:

5. A. gear testing apparatus including rotatable supports for a. pair-o f meshing gears, ini'licating mechanism including a pair of coaxial rotatable members, and motion transmitting connections between said supports and "said members and including a lever having means for adjusting; thcpo ver ratio thereof in accordance with the diameters oi said gears.

6. it. gear testing apparatus including rotatable supports for a pair of meshing gears, indicating mechanism including a pair of coaxial rotatable parts,iriction disks connected for rotation with said gears, :tiriction d .is connected for rotation with said parts, and separate means for transmitting motion from said. first mentioned disks to said second. mentioned disks, one-of said means in. cluding a lover of adjustable power ratio, whereby said indicating member parts may be rotated at substantially the same speed from gears of different pitch ratio.

'4'. A gear testing apparatus including supports for a pair ot'nieshing gears, indicating" mechanism including a pair of rotatable tatable parts, means for transmitting motion from one of said supports to one of said parts, and means for transmitting motion.

from the other of said supports to the other part, said last mentioned means including a iWOSQCtlOIIal longitudinally movable device, and a doublelever having the armsthereof engaging with the sections of said device, the effective length of said l ver arms being adjustable to-vary the relative movements'ot said sect ons;

9. It. gear testing apparatus including a support for a gear to be tested, a rotatable indicating member. said support and said member having friction disks rotatable therewith, a connecting device including a pair oi? rod sections, onehaving' frictional engagement with one disk, and the other having frictional engagement with the other disk, and a lever having a pair of arms. one connected to one rod section, and the other connected to the other rodsection.

10. A gear testing apparatus including a Bill support for gear to be tested, a rotatable indicating member, said support and said member having i'rictionv disks rotatable therewith, a connecting device including a pair of rod sections, one having frictional engagement with one disir, and the other havin frictional engagement With the other disk, and a lever having a pair of arms, one connected to one rod section, and the other connected to the other rod section, the effective lengths of said lover arms being adjustable to vary the relative move-moi ts of said rod sections.

11. A gear testing apparatus including support for a gear to be tested, rotatab e indicating member, said support and said member having friction disks rotatable therewith, a connecting device including a pair of rod sections, one having frictional engagement with one disk, and the other having frictional engagement with the other disk, and a lever having a pair of arms, one connected to one rod section, and the other connected to the other rod section, one of said lever arms being longitudinally adjust able in respect to its fulcrum to vary the power transmission ratio of said lever.

12. A gear testing apparatus having a pair of friction disks connected to the meshing gears, indicating mechanism including a. )an' or co ial arts iihiilllll disks cow nected to said parts, a rod having friction engagement with one of said first mentioned disks and with one of said second mentioned disks, and a second rod formed or" two sec tions, one section engaging with the other of said first mentioned disks and tie second section With the other of said second men tioned disks, and a lever, including a pair of superposed adjacent arms extending in a direction approximately at right angles to the direction of said rods, and having one arm. connected to one of said sections, and. the other connected to the other section, one of said lever arms being adjustable longitudi madly in respect to its fulcrum whereby the adjustment of said lever arm may be made motion tran: ii in accordance nith the relative adpistment or said gear sup orts whereby ditieient gear diameter ratios may be compensated for by correspondi dinerences in motion transmission to si'l indicating mechanism.

is. A gear testing apparatus including a rotatable support for gear to be tested, a rotatable indicating member, a pair of rods, one moved endivise upon the rotation of said gear and the other acting when moved longitudinally, to rotate said indicating mechan sm, a lever having aroller in transverse guided relationship to one of said rods, and second rol er in transverse guided relationshio to the other rod, and means Whereby the distance between one of said rollers and the lever rulcruin may be varied.

15. A. gear testing apparatus including rota-table supports for a pair meshing gears, indicating IIlQCl'lfilllSlD, means tor emitting motion from said supports to ll no mechanism, and means for .justing rue motion transmitting ratio.

to. t apparatus including s a pair of meshing indicating mechanism, and means for Li tting motion rrom each support to its corresponding part o said indicating mechanism, one oi": said means being adapted j! r the adjzistnieid i the i'uotion transmitrat1o.

10 fin indicating 

